Strumigenys sistrura

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Strumigenys sistrura
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Strumigenys
Species: S. sistrura
Binomial name
Strumigenys sistrura
(Bolton, 1983)

Pyramica sistrura casent0102591 profile 1.jpg

Pyramica sistrura casent0102591 dorsal 1.jpg

Specimen labels

Collections note specimens were collected from rainforest and secondary forest litter-samples.

Identification

A member of the Strumigenys loveridgei -group.

Bolton (1983) - The separation of sistrura and its closest relative Strumigenys cryptura from Strumigenys loveridgei is tabulated under the last name. G. sistrura differs from cryptura as follows.

sistrura cryptura
Mandible with 6 enlarged teeth, the basalmost following the lamella without a diastema. Mandible with 5 enlarged teeth, with a short diastema between the basalmost tooth and the lamella.
Basal tooth of mandible not followed by a long broadly spatulate medially projecting hair before the basal lamella. Basal tooth of mandible followed by a long broadly spatulate medially projecting hair before the basal lamella.
Lateral margins of clypeus more or less parallel anterior to the frontal lobes; clypeus narrower. Lateral margins of clypeus divergent anterior to the frontal lobes; clypeus broader.
Appressed spatulate hairs on clypeus relatively large, as long as or longer than the basalmost tooth of the mandible. Appressed scale-like hairs on clypeus minute, conspicuously shorter than the basal most tooth of the mandible.
Arched cephalic hairs at highest point of vertex simple. Arched cephalic hairs at highest point of vertex narrowly spatulate.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Afrotropical Region: Cameroun (type locality), Gabon, Ghana, Ivory Coast.


Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Castes

Nomenclature

The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • sistrura. Glamyromyrmex sistrurus Bolton, 1983: 329, fig. 24 (w.) CAMEROUN. Combination in Pyramica: Bolton, 1999: 1672; in Strumigenys: Baroni Urbani & De Andrade, 2007: 128. See also: Bolton, 2000: 310.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Description

Worker

Holotype. TL 2.0, HL 0.50, HW 0.35, CI 70, ML 0.10, MI 20, SL 0.20, SI 57, PW 0.23, AL 0.52.

Mandible with a principal dental row of 6 enlarged teeth. Basal tooth of mandible slightly smaller than the second, following the basal lamella without a diastema. (The basal lamella partially visible as mandibles are not fully closed.) Second tooth distinctly smaller than the third and the third noticeably smaller than the fourth and fifth teeth which are the largest. Sixth tooth about the same size as the third, followed apically by a pair of denticles which share a common base. In profile the upper and lower mandibular margins divergent from base to apex, the apical (masticatory) margin a strongly downcurved arch but the mandibular dorsal border not upcurved so that it overlaps the level of the anterior clypeal margin. Anterior clypeal margin extremely shallowly concave, almost transverse in full-face view. Upper scrobe margins diverging evenly behind the relatively narrow frontal lobes, not strongly expanded, the preocular laminae just visible in full-face view. Sides of occipital lobes evenly shallowly convex behind the level of the scrobes, rounding to the occipital margin which is shallowly concave and lacks strongly prominent posteriorly projecting lobes. Eyes small, of about 10 ommatidia, situated on the ventral scrobe margin. Antennal scapes weakly clavate, broadest at about the midlength, with the leading edge shallowly convex and equipped with a number of very narrowly spatulate hairs which are subdecumbent to decumbent and directed towards the apex of the scape. Clypeal dorsum densely clothed with short spatulate appressed hairs. Behind the clypeus the hairs more narrowly spatulate and posteriorly becoming gradually even narrower so that by the level of the eye the hairs are simple. All cephalic hairs behind the clypeus are strongly arched forwards and subdecumbent to decumbent. Three pairs of long flagellate hairs present; one pair dorsally close to the occipital margin, one pair at the occipital corners and one pair at the apices of the scrobes. Clypeus smooth and highly polished, remainder of cephalic dorsum strongly reticulate-punctate. Pronotum marginate anteriorly but not laterally. Mesonotum and propodeum marginate laterally, the latter more sharply so than the former, the two areas not separated by a ridge or crest across the dorsum. In profile the dorsal alitrunk convex in outline, highest at the mesonotum and without trace of a metanotal groove, the mesonotum and propodeum forming an even shallow convexity. Propodeum with the teeth incorporated in the infradental lamella. Sides of alitrunk unsculptured except for anterior part of pronotum and some very weak peripheral vestiges. Pronotum and propodeum smooth dorsally, the mesonotum mostly smooth but with faint scattered punctures. Pronotum and mesonotum each with a pair of flagellate hairs. Otherwise dorsal alitrunk only with sparse simple hairs of varying length which arch across the dorsum or curve towards the midline and are sub decumbent to decumbent. Spongiform appendages of pedicel segments massively developed in profile. Petiole node rugulose on the sides and dorsum, only very slightly broader than long in dorsal view and equipped with strongly prominent lateral spongiform appendages which are linked posteriorly by a broad lamina running across the posterior face of the node. Postpetiole smooth and shining, completely surrounded by spongiform tissue which is laminar anteriorly and posteriorly, thickest posterolaterally and narrowest medially. Base of first gastral tergite with a broad strongly ridged transverse band of lamellar spongiform material which has its anterior margin shallowly concave behind the posteromedian margin of the postpetiole. First gastral tergite with short basal costulae. Dorsal surfaces of petiole, postpetiole and first gastral tergite with simple fine hairs, some of those on the petiole subflagellate and others strongly back-curved. Colour black to blackish brown.

Paratypes. TL 1.9-2.0, HL 0.49-0.53, HW 0.34-0.36, CI 67-70, ML 0.10-0.11, MI 19-21, SL 0.18-0.21, SI 53-58, PW 0.22-0.25, AL 0.52-0.55 (11 measured).

As the holotype but the basal and second teeth on the mandible may be about the same size.

Type Material

Holotype worker, Cameroun: Nkoemvon, 2.xi.1980, N49 (D. Jackson) (The Natural History Museum).

Paratypes. 11 workers with same data as holotype and 1 worker with same data but 6.x.1980, N34 (partially dissected to show mandibles) (BMNH; Museum of Comparative Zoology; Musee d'Histoire Naturelle Genève; Ecole Nationale Superieure Agronomique).

References

  • Baroni Urbani, C. & De Andrade, M.L. 2007. The ant tribe Dacetini: limits and constituent genera, with descriptions of new species. Annali del Museo Civico di Storia Naturale “G. Doria” 99:1-191.
  • Bolton, B. 1983. The Afrotropical dacetine ants (Formicidae). Bull. Br. Mus. (Nat. Hist.) Entomol. 46: 267-416 PDF (page 329, fig. 24 worker described)
  • Bolton, B. 1995b. A new general catalogue of the ants of the world. Cambridge, Mass.: Harvard University Press, 504 pp. (page 208, catalogue)
  • Bolton, B. 1999. Ant genera of the tribe Dacetonini (Hymenoptera: Formicidae). J. Nat. Hist. 3 33: 1639-1689 (page 1672, combination in Pyramica)
  • Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028. (page 310, fig. 207 redescription of worker)